Current technology allows different types of wireless and wireline access networks to offer service to subscribers. Support of mobility inter-working between different access technologies, for example, second and third generation (2G/3G) wireless networks, code division multiple access 2000 (CDMA 2000) networks, wireless local area network (WLAN)/Bluetooth® networks, exists to a very limited degree at the radio access network (RAN) level. Standardization work, in the area of WLAN and Global Standard for Mobile Units (GSM)/Universal Mobile Telecommunication System (UMTS) inter-working is in progress. However, the mechanisms being defined address mobility between these networks within the radio access domain. As such, these efforts factor in only wireless, (i.e., RAN), criteria into their schemes. A mechanism is needed whereby “application level” integration is possible across heterogeneous access networks, allowing seamless mobility and inter-working to occur between these systems.